The invention relates to prosthetic devices and methods of forming the same. In particular, the invention relates to a method of forming both transfemoral test and finished thermosetting or laminated sockets, and a lock adapter for connecting a residual limb transfemoral socket to a lock mechanism and prosthetic knee joint.
A transfemoral prosthetic limb is conventionally secured to an amputee's residual limb stump by securing the prosthetic limb to a rigid socket assembly. This may commonly be done by through the use of a locking pin. In this technique, the amputee first dons a sock-like liner formed of an elastomer and may include fabric cover. The lower or distal end of the liner is formed of a rigid material, such as urethane, and the locking pin extends from this rigid bottom. These liners are well known in the art. The pin is extended through the wall of the socket and a distal adapter mounted within or outside of the socket, and can be locked onto a prosthetic lock mounted to the prosthetic limb to secure the prosthesis.
Typically, the pin has a longitudinal series of rack-like serrations and extends through a pin bore of the lock body. The teeth of a pinion gear in the lock body extend into the pin bore to engage the teeth of the lock pin therein. The pinion gear is mounted for one way rotation to permit entry of the lock pin into the pin bore but lock the lock pin against removal. The lock pin can be released only by moving the pinion gear in a direction parallel to its rotational axis until it disengages from the lock pin, e.g., via a manual release button.
In accordance with the conventional transfemoral sockets and attachment locking assemblies, a connecting mechanism is employed in which the lock in the socket is mounted in line with the prosthetic knee. In some amputees, especially those with mid to longer length above knee amputations, this creates a gate disturbance as the knee center is dropped below the knee center of the sound limb. The conventional connecting mechanisms are further incapable of incorporating any flexion in the locking mechanism, which might beneficially accommodate the hip flexion contractures that are often associated with above knee amputations.
Thus, it would advantageous to provide an improved transfemoral socket and lock adapter which allowed for a length off-set between the lock and the prosthetic knee, and which further allowed for the desired degree of flexion, if any. It would further be advantageous to provide improved methods of forming test and finished transfemoral sockets using such lock adapters.